Biomolecular changes on mice caput femur after human recombinant erythropoietin administration

Introduction: Osteonecrosis is a process of death of bone tissue which also causes disturbance in the bone’s blood vessel supply. Administration of recombinant human erythropoietin (rHuEPO) may affect cell proliferation by stimulating angiogenesis and it has been proven that cell proliferation during osteogenesis depends heavily on the formation of new blood vessels. Therefore, EPO has a role in bone regeneration. Methods: This research is an experimental study using Randomized post-test control only group design. Rats were divided into 2 groups, P0 which received dexamethasone injection for 5 weeks and group P1 which received dexamethasone injection combined with rHuEpo for 5 weeks. On the last day of the fifth week, the femoral head of the rats were taken for assessment of VEGF (Vascular Endothelial Growth Factor), BMP-2 (Bone Morphogenic Protein-2), osteocytes, osteoblasts and adipocytes levels. The examination results were then analyzed by using SPSS. Results: From the immunohistochemical and histopathologic examination and further SPSS analysis, it is shown that the number of osteocyte in the femoral heads of rats injected with dexamethasone and rHuEpo were signifcantly higher than those injected with dexamethasone alone (p <0.05). This was also the case with the number of osteoblasts (p <0.05). The expression of BMP-2 and VEGF were also signifcantly higher in rats injected with dexamethasone and rHuEPO (p <0.05). However, the number of adipocytes in the femoral heads of the rats injected with dexamethasone and rHuEpo were signifcantly lower than those injected with dexamethasone alone (p <0.05). Conclusion: Administration of rHuEPO in rats induced with dexamethasone was shown to increase the number of osteoblast, osteocyte, BMP-2 expression, and VEGF, but the number of adipocyte was found to be lower than in rats injected with dexamethasone alone.